Hermetically sealing a container with crushable material and reactive multilayer material

ABSTRACT

Embodiments of the invention include a method for sealing a container. The method includes, providing at least two components of the container, positioning a crushable material between the at least two components, positioning a reactive multilayer material between the at least two components, deforming the crushable material so as to form a seal between the at least two components, chemically transforming the reactive multilayer material so as to join the at least two components.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 10/814,243, filed Apr. 1, 2004, now pending, and claims thebenefits of priority under 35 U.S.C. §§119(e) to U.S. Provisional PatentApplication No. 60/461,196 to David P. VAN HEERDEN, Dale DEGER, TimothyP. WEIHS, and Omar M. KNIO, entitled METHOD OF HERMETIC SEALING ANDRESULTING PRODUCTS, which was filed on Apr. 9, 2003, the entirety of allof which are incorporated herein by reference.

DESCRIPTION OF THE INVENTION

1. Field of the Invention

The invention includes hermetically sealing enclosure components byusing a deformable material and a reactive multilayer joining material.The reactive multilayer joining material may include a reactivemultilayer foil and a fusible material.

2. Background of the Invention

Hermetic sealing is used to protect many sensitive devices from thedamaging effects of exposure to harmful environments. Examples of suchsensitive devices include optical devices, photonic devices, fiberoptics, MEMS and biomedical devices. Generally, sealing is achieved byencapsulating the sensitive component in a leak-tight enclosure,effectively isolating the component from the environment.

Several simple methods exist for sealing sensitive devices andcomponents. Among them are the use of adhesives, epoxies, and mechanicalfasteners. However, each of those methods have disadvantages that mayprevent effective sealing. For example, adhesives and epoxies maydegrade when exposed to heat and humidity. In another example,mechanical fasteners may require tight machining tolerances and maysuffer from potentially low reliability (i.e., not provide asufficiently leak-tight enclosure).

For high-end applications, the preferred methods of sealing includelaser welding, e-beam welding, and thermal resistance welding. Whencarefully applied, these methods result in strong, substantiallyleak-tight, uniform bonds and are consequently quite effective atlimiting the leak rates to very small values. These methods, however,also have drawbacks. For example, implementing these methods requiretight tolerances and have high capital costs. Additional drawbacksinclude the need for surface treatment (e.g., polishing or machining theenclosure after implementing the sealing process), and the possibilitythat the sealing process may cause thermal damage to the enclosurematerials being joined, which in extreme cases results in the loss ofboth the enclosure and the components disposed therein. Thus, there isneed for an improved, more effective means for hermetically sealingsensitive components and devices.

One improved method for hermetically sealing sensitive components anddevices is reactive multilayer joining. Reactive multilayer joining is arelatively new joining technique that is based on sandwiching a reactivemultilayer foil between two layers of a fusible material and the twocomponents to be joined, and then igniting the foil. The ignition of thefoil initiates a self-propagating reaction which results in a rapid risein the reactive foil temperature. The heat released by the reactionmelts the fusible-material layers, and upon cooling, bonds the twocomponents together.

Reactive multilayer joining has been known for quite a while. Theprocess has been described in detail in U.S. Pat. No. 5,381,944, theentirety of which is incorporated herein by reference. Severalimprovements to the process in U.S. Pat. No. 5,381,944 are disclosed inU.S. Provisional Patent Application No. 60/201,292 filed on May 2, 2000and entitled “Reactive Joining Using Multilayer Materials,” the entiretyof which is incorporated herein by reference. The reactive multilayersused in the reactive joining process are nanostructured materials thatare typically fabricated by vapor depositing hundreds of nanoscalelayers that alternate between elements with large, negative heats ofmixing such as Ni and Al. Various implementations of these methods aredisclosed in the following publications, the entirety of all of whichare incorporated herein by reference: U.S. Pat. Nos. 5,538,795;5,547,715; an article entitled “Deposition and Characterization of aSelf-Propagating CuOx/Al Thermite Reaction in a Multilayer FoilGeometry” published in Journal of Applied Physics, Vol. 94(5) on Sep. 1,2003; U.S. patent application Ser. No. 09/846,486 filed May 1, 2001(U.S. Patent Application Publication No. 20020182436); and a chapterentitled “Self-Propagating Reactions in Multilayer Materials” publishedin the 1998 edition of the Handbook of Thin Film Process Technologyedited by D. A. Glocker and S. I. Shah. Alternative methods forfabricating nanostructured reactive multilayers include mechanicalprocessing, which is described in U.S. Pat. No. 6,534,194, the entiretyof which is incorporated herein by reference, and electrochemicaldeposition.

Sealing enclosures with reactive multilayer joining, however, has failedto produce an enclosure with acceptably low leak rates necessary forhigh-end components. This failure can be traced to two well knowneffects: (i) densification of the reactive foil due to the reaction, and(ii) shrinkage of the foil upon cooling from the reaction temperature toroom temperature. Both of these effects cause the formation of cracksalong the foil which are subsequently filled by molten solder or braze.As a result, the reactive joint structure consists of a brittle material(the reacted foil) which is encapsulated by ductile solder or brazematrix. While this result, which can be confirmed by optical microscopy,is essential for the formation of mechanically strong bonds, becausesome of the cracks that form during the reaction are not completelyfilled with the fusible material, the seal may fail or target leak-ratesmay not be achieved. Consequently, reactive joining does not currentlyoffer an adequate means for consistently forming high-end hermeticseals.

SUMMARY OF THE INVENTION

Embodiments of the invention include a method for sealing a container.The method includes, providing at least two components of the container,positioning a crushable material between the at least two components,positioning a reactive multilayer material between the at least twocomponents, deforming the crushable material so as to form a sealbetween the at least two components, chemically transforming thereactive multilayer material so as to join the at least two components.

In various embodiments, the invention may include one or more of thefollowing aspects: positioning a fusible material between the at leasttwo components; chemically transforming the reactive multilayer materialmay include transforming the fusible material so as to join the at leasttwo components; the reactive multilayer material may include a reactivemultilayer foil; the reactive multilayer material may include a fusiblematerial; the seal may be a hermetic seal; chemically transforming thereactive multilayer material may form another seal between the at leasttwo components; the another seal may be a hermetic seal; deforming thecrushable material may include applying force to at least one of the atleast two components; determining the quality of the seal; determiningthe quality of the seal may include determining a leak rate of the seal;providing predetermined quality parameters for the seal; determining thequality of the seal may include determining whether the quality of theseal is within the predetermined quality parameters; chemicallytransforming the reactive multilayer material may include igniting atleast a portion of the reactive multilayer material; deforming thecrushable material may seal an interior of the container from an outsideenvironment; selecting the reactive multilayer material based on thestrength of the seal desired; the crushable material may be configuredto permanently deform; the crushable material may be configured toreversibly deform the crushable material may include a soft metal; thecrushable material may include at least one of copper, gold, aluminum,stainless steel, Kovar, and soft solder; the crushable material mayinclude a compressible polymer; the crushable material may include atleast one of buna rubber, silicon rubber, and viton; the crushablematerial may positioned on an inward side of the reactive multilayermaterial relative to the outside environment; providing a groove on oneof the at least two components; positioning the crushable material mayinclude placing the crushable material in the groove; providing aprotrusion on one of the at least two components; deforming thecrushable material may include deforming the crushable material againstthe protrusion; providing another protrusion on another of the at leasttwo components; deforming the crushable material may include deformingthe crushable material against the another protrusion; providing agroove on one of the at least two components; deforming the crushablematerial may include deforming the crushable material into the groove;providing a corner on one of the at least two components; positioningthe crushable material may include placing the deformable material inthe corner; providing a corner on one of the at least two components;deforming the crushable material may include deforming the crushablematerial into the corner; one of the at least two components may be alid and the other of the at least two components may be a containerbody.

Another embodiment of the invention includes a sealed product. Thesealed product includes at least two components defining a container, acrushable material disposed between the at least two components, thecrushable material being in a deformed state and forming a seal betweenthe at least two components, and a remnant of a chemical transformationof a reactive multilayer material disposed between the at least twocomponents and joining said at least two components.

In various embodiments, the invention may include one or more of thefollowing aspects: the reactive multilayer material may include areactive multilayer foil; the reactive multilayer material may include afusible material; the fusible material may be configured to join the atleast two components; a fusible material may be disposed between the atleast two components; the crushable material may be located on an inwardside of the remnants of the chemical transformation of the reactivemultilayer material; the crushable material and the remnant of thechemical transformation may cooperate to form a hermetic seal betweenthe at least two components; the crushable material may be configured topermanently deform; the crushable material may be configured toreversibly deform; the crushable material may include a soft metal; thecrushable material may include at least one of copper, gold, aluminum,stainless steel, Kovar, and soft solder; the crushable material mayinclude a compressible polymer; the crushable material may include atleast one of buna rubber, silicon rubber, and viton; the crushablematerial may be at least partially disposed in a groove of one of the atleast two components; the crushable material may be at least partiallydisposed in another groove of another of the at least two components;the crushable material may be disposed against a protrusion on one ofthe at least two components; the crushable material may be disposedagainst another protrusion on another of the at least two components;the crushable material may be disposed in a corner of one of the atleast two components; one of the at least two components may be a lidand another of the at least two components may be a container body.

A further embodiment of the invention includes a kit for forming asealed container. The kit includes at least two components which, whenjoined, define the container, a crushable material configured to bepositioned between the at least two components, and a reactivemultilayer material configured to be positioned between the at least twocomponents. The crushable material, in a deformed state, is configuredto substantially form a seal between the at least two components. Atleast a portion of the reactive multilayer material is configured to bechemically transformed so as to join the at least two components.

In various embodiments, the invention may include one or more of thefollowing aspects: the reactive multilayer material may include areactive multilayer foil; the reactive multilayer material may include afusible material; the fusible material may be configured to join the atleast two components; a fusible material configured to be disposedbetween the at least two components; the crushable material may beconfigured to be positioned on an inward side of the reactive multilayermaterial relative to the outside environment; the crushable material anda remnant of the chemical transformation of the reactive multilayermaterial may cooperate to form a hermetic seal between the at least twocomponents; the crushable material may be configured to permanentlydeform; the crushable material may be configured to reversibly deform;the crushable material may include a soft metal; the crushable materialmay include at least one of copper, gold, aluminum, stainless steel,Kovar, and soft solder; the crushable material may include acompressible polymer; the crushable material may include at least one ofbuna rubber, silicon rubber, and viton; one of the at least twocomponents may include a groove configured to at least partially receivethe crushable material; another of the at least two components mayinclude another groove configured to at least partially receive thecrushable material; one of the at least two components may include aprotrusion configured to be disposed against the crushable material;another of the at least two components may include another protrusionconfigured to be disposed against the crushable material; one of the atleast two components includes a corner may be configured to receive thecrushable material; one of the at least two components may be a lid andanother of the at least two components may be a container body.

Yet another embodiment of the invention includes a seal testingapparatus. The seal testing apparatus includes a chamber, an instrumentconfigured to apply pressure to a container disposed in the chamber, aport configured to provide and remove gas from the chamber, a triggerconfigured to initiate a chemical transformation of a reactivemultilayer material, and a leak detector configured to detect a leakfrom the container.

In various embodiments, the invention may include one or more of thefollowing aspects: the reactive multilayer material may be a reactivemultilayer foil; the instrument may be a push rod; the chamber may be avacuum chamber, the port may be configured to create a vacuum in thechamber, the port may be connected to a source of gas; the port may beconnected to a vacuum source.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one (several) embodiment(s) ofthe invention and together with the description, serve to explain theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A–1B are various schematic views of components of a sealedproduct and a portion of a sealed product, according to anotherembodiment of the invention;

FIGS. 2A–2B are various schematic views of components of a sealedproduct and a portion of a sealed product, according to anotherembodiment of the invention;

FIGS. 3A–3B are various schematic views of components of a sealedproduct and a portion of a sealed product, according to a furtherembodiment of the invention;

FIGS. 4A–4B are various schematic views of components of a sealedproduct and a portion of a sealed product, according to yet anotherembodiment of the invention;

FIG. 4C is a schematic view of a portion of a sealed product, accordingto a yet further embodiment of the invention;

FIG. 4D is a schematic view of a portion of a sealed product, accordingto still another embodiment of the invention;

FIGS. 5A–5B are various schematic views of components of a sealedproduct and a portion of a sealed product, according to a still furtherembodiment of the invention;

FIGS. 6A–6B are various schematic views of components of a sealedproduct and a portion of a sealed product, according to anotherembodiment of the invention;

FIGS. 7A–7B are various schematic views of components of a sealedproduct and a portion of a sealed product, according to a furtherembodiment of the invention;

FIGS. 7C–7D are various schematic views of components of a sealedproduct and a portion of a sealed product, according to yet anotherembodiment of the invention; and

FIG. 8 is a schematic view of a seal testing apparatus, according a yetfurther embodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the exemplary embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

FIGS. 1–8 depict various exemplary embodiments of a hermetically sealedproduct and related methods of manufacture. The hermetically sealedproduct may include a judicious combination of a mechanical seal and areactive multilayer joint. Specifically, the hermetic sealed product mayinclude a combination of (1) a “crushable” or “soft” material which,when adequately deformed under pressure, results in a high-quality sealbetween the device and the environment, and (2) a reactive multilayerjoint which maintains the mechanical integrity of the seal after theforce (e.g., pressure) applied to deform the “crushable” or “soft”material is removed.

An exemplary embodiment of a method for manufacturing the hermeticallysealed product may include: (a) positioning one or more crushablematerials between two or more components that define an enclosed space,(b) positioning one or more reactive multilayer foils between the two ormore components (e.g., a lid and a container), (c) applying pressure onthe assembly (e.g., at least one of the two or more components) so as todeform the crushable material and thus seal the enclosed space from theoutside environment, and (d) igniting the one or more reactivemultilayer foils to form the reactive multilayer joint.

The crushable material may be in the form of a wire, gasket, washer,and/or any other suitable material that can be deformed under pressure.The deformation, which may be either permanent or reversible, may besuch that a seal is formed between the two or more components and/oracross the crushable material when pressure is applied to the crushablematerial. The cross-section of the wire, gasket, washer and/or any othersuitable material may range from 1 millimeter to one centimeter indiameter and/or the lengths of these materials may range from severalmillimeters to more than one meter. One of ordinary skill in the artunderstands, however, that the crushable material may have any suitableshape, cross-sectional or otherwise, and/or may have any suitabledimensions.

Some crushable materials may deform permanently (i.e., plastically)while still retaining sufficient mechanical strength to maintain a seal,including when a pressure differential exists between the enclosed spaceand the outside environment. Examples of crushable materials that maydeform permanently include soft metals such as copper, gold, and/oraluminum. Other examples of crushable materials that may deformpermanently may include a hard core (e.g., stainless steel) and a softouter shell (e.g., copper and/or aluminum).

Other crushable materials may reversibly deform during pressurization(i.e., once the pressure is removed, the crushable materialsubstantially returns to its original configuration). Such reversiblycrushable materials may include polymeric materials (e.g., buna rubber,silicon rubber, and/or viton). Reversibly crushable materials have theadvantage that they may be reused after being deformed.

Still other crushable materials may include an outer shell of readilydeformable materials (e.g., copper and/or aluminum) around a spring-likematerial (e.g., stainless steel). Some of the crushable materials setforth herein may be reusable while others may be configured for singleuse only.

Methods of manufacturing a hermetically sealed product may include oneor more reactive multilayer joining methods, examples of which aredisclosed in U.S. Pat. No. 5,381,944, U.S. patent application Ser. No.09/846,486 filed May 1, 2001 (U.S. Patent Application Publication No.20020182436), and U.S. Provisional Patent Application No. 60/201,292filed on May 2, 2000, the entirety of all of which are incorporatedherein by reference.

Methods of manufacturing a hermetically sealed product also may includeone or more methods for obtaining sufficient joint strength between twoor more components. The strength requirement applicable to the seal maybe augmented by the requirement that the joint maintains the deformationof the crushable material after the pressure on the enclosurecomponents, which were previously maintaining the deformation of thecrushable material, is released. For example, the joint should be strongenough to withstand normal jostling of the hermetically sealed product,or other external forces, while at the same time maintaining thedeformation of the crushable material (and hence the seal) after thepressure has been removed from the enclosure components.

The fusible material (e.g., solder or braze) for the reactive joiningprocess may be selected based on one or more relevant factors. Some ofthose factors may include the strength requirement (e.g., due to thetype of crushable material used), thermal fatigue resistance, corrosionresistance, low splatter, and/or vapor emission. The use of brazes asthe fusible material may be preferable if the sealed device is normallysubject to high temperatures during use.

FIGS. 1A and 1B depict an exemplary embodiment of a hermetic sealedproduct 10 and related method of manufacture. As depicted in FIGS. 1Aand 1B, a wire gasket 11 or other suitable crushable (i.e., deformable)material 11 may be positioned in or on a portion of one of the enclosurecomponents, for example, a groove 12 of a lid 13. The groove 12 may beformed in the enclosure component (e.g., lid 13) using any suitablemethod. A reactive multilayer foil 14 may be positioned on and/orbetween one or more surfaces 15, 16 of two or more enclosure components,for example, a lid 13 and a container 17. The enclosure components 13,17 may define an enclosure space 18 within which a device 21 may beplaced. The reactive multilayer foil 14 may also be positioned on and/orbetween one or more layers of fusible material 20. The crushablematerial 11 may then be deformed between the groove 12 of one enclosurecomponent 13 and the surface 16 of another enclosure component 17, forexample, by applying pressure to any appropriate portion (e.g., the topof the lid 13) of one of the enclosure components using any suitablemethod. Such deformation of the crushable material 11 may seal theenclosed space 18 and/or the device 21 from the external environment.The reactive multilayer foil 14 may then be ignited and form a strongmechanical bond between the enclosure components, for example, the lid13 and the container 17. The strong mechanical bond may be formed byeither the bonding of fusible materials 20 to the enclosure components13, 17, or directly bonding the enclosure components 13, 17. Anypressure on the one or more of the enclosure components may then beremoved, and the result is a sealed enclosure 10 configured to maintaina sufficiently leak-tight seal with sufficient integrity for arelatively long period of time.

In various embodiments, the reactive multilayer foils, joiningmaterials, and/or other suitable “fusible” material may be positioned onany side and/or any portion of the reactive multilayer. The fusiblematerial layers may be in any suitable form, for example, afree-standing sheet, a layer that is pre-deposited onto the enclosurecomponent (e.g., the container and/or the lid), and/or a layer that ispre-deposited onto the foil surface. These and other suitable forms aredisclosed in U.S. Pat. No. 5,381,944, U.S. patent application Ser. No.09/846,486 filed May 1, 2001 (U.S. Patent Application Publication No.20020182436), and U.S. Provisional Patent Application No. 60/201,292filed on May 2, 2000. Examples of fusible material include solder and/orbraze. The solder and/or braze may be deposited onto the enclosurecomponents, may be a free-standing sheet that is positioned between thefoil and/or enclosure components, and/or may be deposited onto the foilsurface.

FIGS. 2A and 2B depict another exemplary embodiment of a hermetic sealedproduct 30 and related method of manufacture. This embodiment issubstantially similar to the embodiment set forth in FIGS. 1A and 1B,except that the surface of one of the enclosure components (e.g., thecontainer 31) may include a protrusion 32 (e.g., ridge) configured tointeract with the crushable material 33 disposed in or on anotherenclosure component 34. For example, the protrusion 32 may be disposedsubstantially opposite the groove 35 on the other enclosure component,(e.g., the top lid 34). The protrusion 32 may have any suitable shapeand/or dimension, such as a ridge-shape as depicted in FIGS. 2A and 2B,and may be formed on the surface 36 of the enclosure component 31 usingany suitable method. This arrangement may be advantageous in that due tothe interaction between the protrusion 32 and the crushable material 33disposed in or on the enclosure component, less pressure may be requiredto deform the crushable material (e.g., wire gasket 33) than in thearrangement of FIG. 1.

FIGS. 3A and 3B depict a further exemplary embodiment of a hermeticsealed product 50 and related method of manufacture. This embodiment issubstantially similar to the embodiments set forth in FIGS. 1A–1B and2A–2B, except the crushable material (e.g., wire gasket 51) is disposedin both a groove 52 of one of the enclosure components (e.g., in the toplid 53) and prior to deformation is disposed substantially opposite toan opposing groove 54 (e.g., trough) on another of the enclosurecomponents (e.g., the container 55). The trough 54 or groove 54 may bedisposed on a surface 56 of the enclosure component 55 that is raisedrelative to another surface 57, for example, the surface 56 on which thereactive foil 58 may be disposed. During deformation, the crushablematerial 51 is deformed between the groove 52 and the trough 54. Theadvantage of this arrangement is that the trough 54 or groove 54 may beeasier to machine than the protrusion 32 in FIGS. 2A–2B, and may be lessvulnerable to damage during handling than either the smooth surface 16in FIGS. 1A–1B or the protrusion 32 in FIG. 2A–2B. Deforming thecrushable material 51 to form the seal requires a pressure similar tothe pressure applied to the arrangement in FIGS. 2A–2B (i.e., lower thanthe pressure applied in arrangement of FIGS. 1A–1B).

One of ordinary skill in the art recognizes that any of the features inany of the embodiment set forth herein may be reversed, interchanged,and/or combined with any other feature set forth herein. For example,FIGS. 4A and 4B depict an configuration similar to the configuration inFIGS. 1A and 1B except that the crushable material 71 is disposed in agroove 72 on the container 73 and the corresponding surface of the lidis configured to interact with the reactive multilayer. In anotherexample, FIG. 4C depicts a configuration similar to the configuration inFIGS. 2A and 2B except that the crushable material 81 is disposed in agroove 82 on the container 83 and the protrusion 84 is disposed on thelid 85. In a further example, FIG. 4D depicts a configuration similar tothe configuration in FIGS. 3A and 3B except that the crushable material91 is disposed in a groove 92 on the container 93 and the opposingtrough 94 or groove 94 is on the lid 95.

FIGS. 5A and 5B depict yet another exemplary embodiment of a hermeticsealed product 100 and related method of manufacture. In thisembodiment, a crushable material (e.g., wire gasket 101) is disposed ina corner 102 machined (or otherwise manufactured) in one of theenclosure components (e.g., the container 103). Thus, unlike the otherembodiments set forth herein, additional machining (or othermanufacturing) steps may be need to be performed on one or more of theenclosure components so as to provide satisfactory fits for thecrushable material 101 and/or the reactive multilayer 104. As pressureis applied to one or more of the enclosure components, the crushablematerial 101 may be deformed in the corner 102 by a portion of the otherenclosure component (e.g., a surface 105 on a lid 106) and mayconsequently seal the enclosed interior space 107 defined by theenclosure components (e.g., the lid 106 and the container 103). Thereactive multilayer foil 108 of the reactive multilayer 104 may then betriggered and/or ignited so as to bond the substantially adjacentportions of the enclosure components (e.g., the outer lips of the lid106 and container 103) and/or bond the fusible materials 109 to theenclosure components 103, 106. Long-term integrity of the seal isconsequently achieved. The implementation of this sealing configurationand/or method may be advantageous because it may require less sealingpressure (e.g., to deform the crushable material) than theconfigurations and/or methods set forth in FIGS. 1A–4D. Anotheradvantage this configuration and/or method shares with theconfigurations and/or methods set forth in FIGS. 1A–4D is that, in casethe deformation of the crushable material does not form an adequateseal, the crushable material may be discarded prior to triggering (e.g.,igniting) the reactive multilayer foil and the sealing procedure may berepeated with another crushable material.

FIGS. 6A and 6B depict a yet further exemplary embodiment of a hermeticsealed product 120 and related method of manufacture. In thisembodiment, the opposing surfaces 121, 122 of the two or more enclosurecomponents 123, 124 include protrusions 125, 126 (e.g., sharp-edgeridges) configured to interact with a crushable material 127. Tomaintain their sharpness, the ridges 125, 126 may need to be protectedprior to placement of the crushable material 127. When the two or moreenclosure components 123, 124 are aligned prior to sealing, theirrespective ridges 125, 126 may substantially oppose each other. Theridges 125, 126 may be a hard material, at least relative to the gasket,washer, or other suitable crushable material 127. The gaskets, washers,and/or any other suitable softer (e.g., relative to the ridges 125, 126and/or enclosure components 123, 124) and/or crushable material 127 maybe placed between corresponding ridges 123, 124. The gaskets 127 and/orwashers 127 may need to be properly and/or positioned on the ridges 125,126 in order to form an effective seal upon deformation. Sealing may beaccomplished by exerting sufficient pressure on one or more of theenclosure components 123, 124 so that the harder sharp-edge ridges 125,126 suitably deform the softer crushable material 127. Potentialadvantages of this approach include (1) it may be easier to handlesimple gaskets and/or washers than other materials, (2) there may belower requirements for surface flatness and finish (e.g, of theenclosure components), and/or (3) less pressure may needed to deform thecrushable material and form a suitable seal, for example, relative tothe other embodiments set forth herein.

FIGS. 7A–7D depict still more exemplary embodiments of a hermetic sealedproduct 140, 160 and related method of manufacture. In these embodimentsthe use of a soft washer, gasket, or other discrete crushable materialmay be eliminated, and instead a sharp-edge ridge 141, 161 or protrusion141, 161 on one of the enclosure components 142, 162 may used to pressdirectly against and into the softer surface of the other enclosurecomponent 143, 163. The soft or hard materials may preferably beselected so as to avoid a galvanic couple. FIGS. 7A and 7B depict anembodiment where the sharp-edge ridge 141 of the container 142 pressesdirect against and/or into softer material of the lid 143. FIGS. 7C and7D depict an embodiment where the sharp-edge ridge 161 of the lid 162presses direct against and/or into softer material of the container 163.One of ordinary skill in the art understands that only a portion of eachof the enclosure components may be made of the harder and/or softermaterial, for example, as may be necessary to effect the seal betweenthe enclosure components. Some advantages of these designs include lowermachining effort (i.e., easier to manufacture), and the elimination ofwires, gaskets, washers, and/or other discrete crushable materials. Oneadditional advantage of this embodiment, and especially to thearrangement of FIGS. 7A and 7B, is that the enclosure component withoutthe special geometric features (e.g., the lid 143 in FIGS. 7A and 7B, orthe container 163 in FIGS. 7C and 7D) may be discarded and/or replacedif the seal is found to be inadequate. The other component may also bereused. Another advantage is that because the enclosure component madeof the softer and/or crushable material (e.g., the lid 143 in FIGS. 7Aand 7B, or the container 163 in FIGS. 7C and 7D) does not includespecial geometric features, that enclosure component may be relativelyinexpensive to manufacture and/or replace relative to the otherenclosure components set forth herein.

One advantage of the invention, exemplary embodiments of which are setforth herein, is that the sensitive components positioned within theenclosed space of the container are protected by the sealing surfaceand/or crushable material from the flow of the fusible material (e.g.,solder or braze) that is used in the reactive joining process.Specifically, in previous methods where no sealing surface and/orcrushable material was used, the fusible material, while in its moltenstate, sometimes may leak into the enclosed space of the container, andconsequently damage the sensitive component housed therein. In theembodiments disclosed herein, however, because the sealing surfaceand/or crushable material is positioned inward of the fusible material,that is, between the fusible material and the enclosed space, thepossibility that the fusible material could flow into the enclosed spaceand damage the sensitive component housed therein is substantiallyreduced, if not effectively eliminated. The molten fusible material(e.g., solder or braze) would be trapped by the sealing surface and/orcrushable material (e.g., wire, gasket, washer and its support, or bysharp-edge ridge). This is an advantage over conventional reactivejoining methods.

Another advantage of the invention, exemplary embodiments of which areset forth herein, is that the quality of the seal (e.g., due to thesealing surface and/or crushable material) can be assessed and ensuredbefore the seal is made permanent (e.g., through reactive joining). Thisis the case because prior to foil ignition and reactive bonding, theseal may be obtained by applying pressure to one or more of theenclosure components and deforming the sealing surface and/or crushablematerial. Should the quality of the seal from this application ofpressure be deemed unsatisfactory, one or more portions of the enclosureassembly may be adjusted without risking the loss of the sensitivecomponent located within the container. Such adjustments may includereplacing of the wire, gasket, washer, and/or other suitable material,polishing the surfaces of one or more enclosure components (e.g., thelid and/or container), or re-tooling the faulty portions of theenclosure assembly. This ability to assess the quality of the seal priorto permanently sealing the enclosure is a substantial advantage overmost alternative approaches where sealing is achieved through permanentor irrecoverable alterations to the assemblies. Examples of suchalternatives include laser welding, soldering or brazing, as well as theuse of screws or mechanical fasteners.

In various embodiments of the invention, verification of the quality ofthe seal prior to the formation of the permanent bond can be achievedusing a seal testing apparatus. An example of such a seal testingapparatus 200 is shown in FIG. 8. As depicted in FIG. 8, the apparatus200 may include one or more vacuum chambers 201, a push-rod 202 orsimilar mechanism for positioning one of the enclosure components (e.g.,the lid 203) relative to the other enclosure component (e.g., on top ofthe container 204) and/or applying pressure on one or more portions ofthe enclosure, one or more inlets 205 for filling the chamber 201 with agas (for example, an inert gas such He or Ar) or a gas mixture (forexample, an inert gas mixture containing He), one or more outlets 206for evacuating from the chamber 201 a gas (for example, an inert gassuch He or Ar) or a gas mixture (for example, an inert gas mixturecontaining He), and means 207 for igniting the reactive multilayer 208(e.g., a reactive multilayer foil that may or may not have fusibleand/or joining materials). The push rod 202 may include a bellow 212,for example, assist in moving the push rod 202 and/or seal the interfacebetween the push rod 202 and the wall of the chamber 201 through whichthe push rod 202 extends. The inlet and outlet may also be the same port(i.e., gas or a gas mixture may be filled to and/or evacuated from thechamber by the same inlet, outlet, and/or port). Examples of means 207for igniting the reactive multilayer 208 include an internal devicewhich may provide an electrical, thermal or mechanical stimulus, and/oran external device such as laser. In the case where the means forigniting the reactive multilayer is a laser, an optical path may beprovided through the walls of the vacuum chamber 201.

In various embodiments, the process for manufacturing a hermeticallysealed product may include one or more of the following steps: (1)position the two or more enclosure components (e.g., container and lid)in the chamber 201, (2) evacuate the chamber 201 using suitable meansknown in the art, for example, a vacuum pump connected to the outlet 206(particularly to remove air and moisture), (3) backfill the chamber 201with a gas or a gas mixture using suitable means known in the art (forexample, filling the chamber 201 with inert gases via the inlet 205),(4) position one of the enclosure components relative to anotherenclosure components (e.g., place the lid 203 on top of the container204) and apply pressure to at least one of the enclosure components(e.g., to the lid 203 via the push rod 202) in order to seal theinterior chamber 209 and/or device 210 from the rest of the chamber 201(e.g., by deforming a crushable material, placing a sharp edged ridge ofone of the enclosure components into another of the enclosurecomponents, and/or any variation of any of the embodiment set forthherein), (5) evacuate the chamber 201 using suitable means known in theart, for example, a vacuum pump connected to the outlet 206, (6)measure/verify the leak rate using any suitable means and/or methodsknown in the art (e.g., a leak detector 211 connected to the outlet206). If the measured leak rate is satisfactory, ignite the foil and/orreactive multilayer 208 and thus permanently seal the enclosure. If themeasured leak rate is unsatisfactory, address the one or moredeficiencies and repeat one or more steps of the process. One advantageof the invention is that it eliminates or minimizes the loss ofsensitive components during the sealing process.

One of ordinary skill in the art realizes that any of the aforementionedaspects of any of the embodiments may be combined with any of theaspects of any of the other embodiments. Moreover, one of ordinary skillin the art realizes that any of the aforementioned aspects may beremoved from any of the embodiments without departing from the truescope of the invention. In addition, one of ordinary skill in the artrealizes that the embodiments disclosed in any of the referencesincorporated herein by reference are exemplary only, and despite whatmay be written in the disclosures, do not limit the invention in anyway.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

1. A method for sealing a container, comprising: providing at least twocomponents of the container; positioning a crushable material betweenthe at least two components; positioning a reactive multilayer materialbetween the at least two components; deforming the crushable material soas to form a seal between the at least two components; and chemicallytransforming the reactive multilayer material so as to join the at leasttwo components.
 2. The method of claim 1, further comprising positioninga fusible material between the at least two components; whereinchemically transforming the reactive multilayer material includestransforming the fusible material so as to join the at least twocomponents.
 3. The method of claim 1, wherein the reactive multilayermaterial includes a reactive multilayer foil.
 4. The method of claim 1,wherein the reactive multilayer material includes a fusible material. 5.The method of claim 1, wherein the seal is a hermetic seal.
 6. Themethod of claim 1, wherein chemically transforming the reactivemultilayer material forms another seal between the at least twocomponents.
 7. The method of claim 1, wherein chemically transformingthe reactive multilayer material stabilizes the seal between the atleast two components.
 8. The method of claim 6, wherein the another sealis a hermetic seal.
 9. The method of claim 1, wherein deforming thecrushable material includes applying force to at least one of the atleast two components.
 10. The method of claim 1, further comprisingdetermining the quality of the seal.
 11. The method of claim 10, whereindetermining the quality of the seal includes determining a leak rate ofthe seal.
 12. The method of claim 10, further comprising providingpredetermined quality parameters for the seal, wherein determining thequality of the seal includes determining whether the quality of the sealis within the predetermined quality parameters.
 13. The method of claim1, wherein chemically transforming the reactive multilayer materialincludes igniting at least a portion of the reactive multilayermaterial.
 14. The method of claim 1, wherein deforming the crushablematerial seals an interior of the container from an outside environment.15. The method of claim 14, wherein the crushable material is positionedon an inward side of the reactive multilayer material relative to theoutside environment.
 16. The method of claim 1, further comprisingselecting the reactive multilayer material based on the strength of theseal desired.
 17. The method of claim 1, wherein the crushable materialis configured to permanently deform.
 18. The method of claim 1, whereinthe crushable material is configured to reversibly deform.
 19. Themethod of claim 1, wherein the crushable material includes a soft metal.20. The method of claim 19, wherein the soft metal includes at least oneof copper, gold, aluminum, stainless steel, Kovar, and soft solder. 21.The method of claim 1, wherein the crushable material includes acompressible polymer.
 22. The method of claim 21, wherein thecompressible polymer includes at least one of buna rubber, siliconrubber, and viton.
 23. The method of claim 1, further comprisingproviding a groove on one of the at least two components; whereinpositioning the crushable material includes placing the crushablematerial in the groove.
 24. The method of claim 1, further comprisingproviding a protrusion on one of the at least two components; whereindeforming the crushable material includes deforming the crushablematerial against the protrusion.
 25. The method of claim 24, furthercomprising providing another protrusion on another of the at least twocomponents, wherein deforming the crushable material includes deformingthe crushable material against the another protrusion.
 26. The method ofclaim 1, further comprising providing a groove on one of the at leasttwo components, wherein deforming the crushable material includesdeforming the crushable material into the groove.
 27. The method ofclaim 1, further comprising providing a corner on one of the at leasttwo components, wherein positioning the crushable material includesplacing the deformable material in the corner.
 28. The method of claim1, further comprising providing a corner on one of the at least twocomponents, wherein deforming the crushable material includes deformingthe crushable material into the corner.
 29. The method of claim 1,wherein one of the at least two components is a lid and the other of theat least two components is a container body.